lucy-ng:CASE

To elucidate a chemical structure from NMR data without database matches, you perform de novo structure deduction using CASE. This method applies iterative data-driven constraints from your molecular formula and NMR correlations to converge on a unique solution.

For computer-assisted structure elucidation, you need the molecular formula, 13C spectrum, HSQC, and HMBC data. Supplying optional DEPT-135 and COSY data strengthens constraints to construct robust solver input and converge on a unique solution.

You should use de novo structure elucidation when a compound is suspected to be novel or when dereplication returns no matches. It enables first-principles structure deduction via iterative data-driven constraints rather than relying on existing database entries.

To solve CASE structures using HSQC and HMBC correlations, guide an AI agent stepwise from the molecular formula to constraint generation. The workflow executes a solver, converts results to SMILES, ranks candidates, and analyzes HMBC path lengths for iterative refinement.

You cannot run robust LSD structure elucidation with only 13C and HSQC data because HMBC is strictly required. The solver needs HMBC to establish long-range correlations, while DEPT-135 and COSY are optional additions that further strengthen constraints.

A limitation of CASE for novel compound identification is its strict data requirement for molecular formula, 13C, HSQC, and HMBC. Without these inputs, the solver cannot construct robust constraints, and the iterative refinement workflow may hit dead ends without proper logging.